DWP modelling shows that with automatic enrolment median private pension income could rise to between £153 and £195 a week by 2070. Without these reforms, median weekly private pension income would only reach between £86 and £106.
The research, Workplace Pension Reforms: Baseline Evaluation Report, describes the pensions landscape before automatic enrolment is introduced this year, and employers' preparation for the reforms.
The report shows three quarters of large employers support automatic enrolment; private sector pension participation has fallen from 7.9 million (55%) in 2003 to 5.8 million (42%) in 2011; low earners, individuals working for small and micro employers and those aged 22 to 29 show steep declines in pension participation; and private sector workplace pension saving has fallen from £39.3 billion in 2007 to £35 billion in 2011.
Pensions minister Steve Webb said: "This October we will introduce the most important changes in pensions for a century to help people save and avert a pensions crisis in the future.
"We are living longer yet 11 million of us are not saving enough for retirement.
"Automatic enrolment will reverse this trend as millions will have a workplace pension and could double their private pension income, on top of a reformed state pension.
The research will be updated every year to track the impact of automatic enrolment.